My Security Camera System and Gateway

I was a witness to the Mailman being assaulted by my neighbor Lawnguy and had to testify against him shortly after this all started happening my cameras are showing weird background heads looking over my fence it’s hard to explain but I am not seeing things it’s like the whole scenery is different but sometimes the head is of my neighbors I think they hired someone to do this. I have a 4 channel NVR IP cameras bought in March both seller and manufacturer say this is impossible but I’m living it and know I’m not Losing it . I don’t have a lot of money and have a sister with CP I’m taking care of I do want a quote on repair and to keep it from happening again if you do this and have heard of what I’m describing and please let me know . I feel violated by this and am not crazy .